In the 3G cellular telephony system known as WCDMA, (Wideband Code Division Multiple Access), the system is divided into cells, and has a number of Radio Base Stations (RBS) which monitor and control traffic to and from users (UE) in the cells. The node “above” the RBSs is known as the Radio Network Controller (RNC), with one of the functions of the RNC being to monitor and control the RBSs.
The traffic from the RBSs to the RNC can be expressed as a number of flows. Accordingly, the system needs to comprise a function for monitoring and controlling the flows from the RBSs to the RNC. The purpose of this monitoring and controlling is, inter alia, to control congestion over the interface between the RBSs and the RNC, and also over the interface between the RNC's in the system.
There are several possibilities for controlling such flows, depending on the cost of the transmission and the properties of the traffic. Such possibilities are e.g. so called “overprovisioning” or admission control, or a combination of those methods.